PROGRAM d10r6(input,output);
(* driver for routine POWELL *)
CONST
   ndim=3;
   ftol=1.0e-6;
TYPE
   glnarray = ARRAY [1..ndim] OF real;
   glndim = glnarray;
   glnpbynp = ARRAY [1..ndim,1..ndim] OF real;
   gl3array = glnarray;
VAR
   ncom : integer;
   pcom,xicom : glnarray; 
   fret : real;
   i,iter,j,np : integer;
   p : glnarray;
   xi : glnpbynp;

(*$I MODFILE.PAS *)
(*$I BESSJ0.PAS *)

FUNCTION fnc(x: gl3array): real;
(* Programs using FNC must define the type
TYPE
   gl3array = ARRAY [1..3] OF real;
in the main routine. *)
BEGIN
   fnc := 0.5-bessj0(sqr(x[1]-1.0)+sqr(x[2]-2.0)+sqr(x[3]-3.0))
END;

(*$I F1DIM.PAS *)

FUNCTION func(x: real): real;
BEGIN
   func := f1dim(x)
END;

(*$I MNBRAK.PAS *)

(*$I BRENT.PAS *)

(*$I LINMIN.PAS *)

(*$I POWELL.PAS *)

BEGIN
   np := ndim;
   xi[1,1] := 1.0; xi[1,2] := 0.0; xi[1,3] := 0.0;
   xi[2,1] := 0.0; xi[2,2] := 1.0; xi[2,3] := 0.0;
   xi[3,1] := 0.0; xi[3,2] := 0.0; xi[3,3] := 1.0;
   p[1] := 1.5; p[2] := 1.5; p[3] := 2.5;
   powell(p,xi,ndim,np,ftol,iter,fret);
   writeln('Iterations:',iter:3);
   writeln;
   writeln('Minimum found at: ');
   FOR i := 1 to ndim DO write(p[i]:12:6);
   writeln;
   writeln;
   writeln('Minimum function value =',fret:12:6);
   writeln;
   writeln('True minimum of function is at:');
   writeln(1.0:12:6,2.0:12:6,3.0:12:6)
END.